Rattling noise when A.C. is on

[comncense]

Ok, I know I found this question on here before sometime last year, but can't find the thread now. used: Anyway, lately whenever I'm in my car with the A.C. on, i get this weird noise like maybe the fan is rubbing against a belt somewhere in the engine bay. I only hear it when the a.c. is on. It used to do it a while ago but then stopped, but as of this weekend it has started doing it again and the volume of the noise increases as the car's speed increases. Any ideas? I still have warranty so I could take it to the dealer but i hate being without a car, so if it's something i can fix myself I'd rather do it that way.

[peterkulesza]

pulley bearing? listen with a stethoscope.

[///Matt]

I had an issue similar...Whenever I had the A/C on it would make a slight vibration and sounded like something was rubbing. It turned out that a small piece of my auxillary fan blade was chipped off and that threw the fan off balance.